A gas turbine engine may typically include one or more stacks of rotating elements, such rotor stacks, associated with one or more sections of the engine. A rotor stack may include several longitudinally spaced apart blade-carrying disks of successive stages of the section. A stator structure may include circumferential stages of vanes longitudinally interspersed with the rotor disks. The rotor disks are secured to each other against relative rotation and the rotor stack is secured against rotation relative to other components on its common spool (e.g., the low and high speed/pressure spools of the engine). Various systems for tying rotor disks together may comprise keying arrangements, which may be associated with the maintenance of a longitudinal compressive force across the disk stack so as to maintain the engagement. Other arrangements may use extraneous components such as fasteners or bolts.